Printer with swiveling pushrods



March 18, 1969 R. H. HARRINGTON ET AL 3,433,153

PRINTER WITH SWIVELING PUSHRODS Filed D80. 29, 1967 as as FIG. 3

IN VE' N TOPS RICHARD H. HARRINGTON MICHAEL A. HEN/(EL ATTORNEY United States Patent 3,433,153 PRINTER WITH SWIVELING PUSHRODS Richard H. Harrington, Vestal, and Michael A. Henkel,

Endwell, N.Y., assignors to International Business Machines Corporation, Armonk, N.Y., a corporation of New York Filed Dec. 29, 1967, Ser. No. 694,585

US. Cl. 101-93 Claims Int. Cl. B41 1/32 ABSTRACT OF THE DISCLOSURE A plurality of print hammers for impacting a document to print thereon are mounted in spaced apart relation on a support member movable to position the hammers at extreme and one or more intervening print positions, and are actuated to print by stationary actuating means operatively connected to the hammers by swiveling pushrods.

Field of invention The invention relates to printers having spaced apart print hammers which are movable to print in the extreme and intervening spaces.

Description of prior art Printers are known heretofore such as shown in US. Patent No. 3,241,480, which issued on Mar. 22, 1966, to James M. Cunningham, entitled, Print Hammer Mechanism and Pressure Control Means in High Speed Printers, and in which a print hammer and actuating mechanism is provided for each and every print position. Other printers are also known in which spaced apart print hammers are used and the entire mechanism, including the hammers and actuating means thereof, is moved to print in the intervening spaces.

Summary of invention Generally stated, it is an object of this invention to provide a simple and inexpensive printer.

More specifically, it is an object of the invention to provide a hammer structure for a printer with spaced hammers that are incremented in one or more steps to print in the extreme and intervening positions, without requiring the electromagnetic actuating means therefor to be incremented with the hammers.

It is also an object of this invention to provide for using swiveling pushrods for connecting stationary electromagnet actuating means to print hammers mounted on a movable hammer support.

Another object of the invention is to provide in a printer for pivotally mounting a pushrod at one end adjacent an actuating electromagnet, and for operatively connecting the other end to move with a movable hammer support for operating a single print hammer in a plurality of diiferent print positions.

Yet another object of this invention is to provide for pivotally mounting a plurality of print hammers in slots in a movable support, and for actuating the hammers by means of slender pushrods which are slidably disposed in elongated guides pivotally supported adjacent to the actuating armature of an electromagnet at one end, and secured at the other end relative to the movable support by portions of the guide interfitting with the slots in which the hammers are mounted.

In a preferred embodiment of the invention, a plurality of print hammers are disposed along a print line at every other one of a plurality of print positions, being pivotally supported in slots in an elongated support member which is itself movable along the print line. The support memice her is slidably disposed on a bar, and is moved to position the hammers in the intervening and extreme print positions by means of a rack and pinion structure driven by a stepping motor. The print hammers are actuated by stationary print magnets individual to each hammer, having pushrods which are disposed in guides having one end pivotally mounted adjacent the armature of its electromagnet, and the other end secured relative to the movable support by a projecting portion interfitting in the slot in which its associated hammer is positioned.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawmgs.

Description of the drawings In the drawings:

FIGURE 1 is a partial plan view of a print hammer operating mechanism embodying the invention in one of its forms,

FIGURE 2 is a front elevational view in part of the same mechanism shown in FIGURE 1, showing the motor,

FIGURE 3 is a side elevational view partly in section of the hammer operating mechanism of FIGURES 1 and 2,

FIGURE 4 is an enlarged partial view of a portion of movable support and pushrod guide shown in FIGURE 3,

FIGURE 5 is an enlarged partial plan view of the same portion of the movable support and pushrod guide mechanism shown in FIGURE 4,

FIGURE 6 is a schematic plan view of a portion of an alternate print hammer and pushrod structure showing a different form of the invention, and

FIGURE 7 is an enlarged partial plan view of the pushrod and hammer mechanism of FIGURE 6 showing in detail the end portions of the pushrod structure.

Description of preferred embodiments FIGURES l, 2 and 3 of the drawings are partial, plan, front elevation, and side elevation views, respectively, of a printer apparatus of one type with which the present invention may be used. The structure shown is substantially identical with that in the James M. Cunningham patent hereinbefore referred to, and as therein shown, printing occurs when any one of a plurality of print hammers 12 are actuated by means of pushrods 14. The pushrods have enlarged end portions 15 of polyurethane or the like, and are slidably disposed in elongated guide members 16 and 16' extending from adjacent pivotally mounted operating armatures 18 of electromagnetic actuating means including an electromagnetic core 20 and -a solenoid operating winding 22 (shown in part) for attracting the arm-ature 18 to adjacent their associated hammers, for guiding the pushrods 14 to enable them to actuate their respective print hammers 12. As shown, the pushrods 14 with their respective guide members 16 and 16' are substantially identical, the primed numbered pushrods and guide members being slightly longer, so that their actuating means may be located to the rear of the actuating means for the pushrods 14, to facilitate maximum utilization of the available space.

The printer structure, shown in the Cunningham patent referred to, is a back printer, in which the hammers =12 impact a document and an associated carbon or type ribbon against type characters on a moving chain, train, or belt. The structure of the present invention is not limited to a back printer and the hammers 12 may be used either to impact a document and ribbon against type characters on a movable type character supporting member as in the Cunningham patent, or they may be used to actuate a movable type character bearing element on a chain, train or belt against a document and a suitable ribbon as in a front printer.

Instead of having the plurality of print hammers 12 positioned in adjacent print positions along a print line and each with their individual pushrods and actuating means disposed in generally the same fixed operating relation, as shown in the Cunningham patent, the print hammers 12 of the present invention are disposed to be positioned in spaced apart relation, being for example, positioned in every other print position or some other similar arrangement such as in every third or every fourth print position. As shown in FIGURES 1, 2 and 3, the print hammers 12 are positioned in slots 24 which are uniformly spaced along a substantially vertical web or flange 28 of a movable support member 26 and which extends substantially the length of the support, the slots being, for example, so spaced as to be located opposite alternate print positions. The support member 26 extends substantially the length of the print line, and may comprise a lower body portion 30 positioned along the lower edge of the web 28, and having an elongated cylindrical opening 32 extending throughout the length thereof for receiving a rod or tube 34 which is rigidly mounted to a fixed portion of the printer frame 36 for providing a support on which the support member 26 may slide longitudinally, The body portion 30 is provided with a depending tab 36 positioned intermediate its ends, and to which may be secured by means of a bolt 38, a guide roller 40 for engaging the under surface 41 of a fixed guide member 42 projecting from another portion 44 of the frame of the machine. The roller 40 and the guide 42 provide mating surfaces which resist counterclockwise rotation of the support member 26 about the support rod 34, and maintain it in substantially the operating position shown in FIGURE 3. Movement of the support member along the support rod 34 may be obtained by means of a rack and pinion strutcure comprising rack teeth 49 on a downwardly projecting tab or flange 48 on the underside of the body 30 of the support member, which mesh with teeth 52 on a clamp type pinion member 51 secured to the shaft 54 of a stepping motor shown generally at 56.

Referring particularly to FIGURE 3 of the drawings, it will be seen that each of the hammers 12 comprises generally a hammer shaped head portion 66 for impacting a document or type bearing element, and a central stem portion 68 having at the lower end an enlarged boss 69 for receiving an elongated pivot pin 70 upon which the hammer 12 pivots. The pin 70 is disposed on the support member 26 by being positioned in an elongated slot 71 extending along the front side of the web 28 of the sup port member. Each hammer is provided with a depending tab 72 at the lower end of the boss 69 for engaging a restoring spring 74 positioned in a recess 76, which may be drilled or otherwise provided in the support member adjacent the lower end of the slot 24. The pivot pin 7 t is retained in the slot 71 by means of fingers projecting from clamp plates 82 secured to the web of the support member 26 by means of screws 84.

Since the support member 26 is movable longitudinally of the support rod 34, provision must be made for maintaining alignment of the pushrods 14 with their respective hammers 12 when the support member is moved to different operating positions. For this purpose, the pushrods have their guide members 16 and 16 provided with depending pivot pins 88 projecting downwardly from the guide members '16 and 16' adjacent the armature 18. The pivot pins 88 and 88' may be disposed in openings 90 and of stationary support members 92 and 92 extending longitudinally along the print line.

The other ends of the guide members 16, 16' are maintained in operating relation with their respective hammers 12 by means of horizontally projecting flange portions 94, as shown in FIGURES 3, 4 and 5, which extend beyond the end of the guide members 16 and 16', being positioned, for example, in a horizontally extending slot 96 on the back side of the support member 26. The flange 94 is provided with a depending central web portion 98 which is slightly narrower than the associated slot 24 in which it is positioned, and has a rounded or bulbous end portion 100 which provides a relatively snug fit in the slot 24. This arrangement permits stepping of the support member 26 in one or more steps to different intervening and extreme print positions without any binding of the guides 16, 16 in the slots 24, while the pivoted ends of the pushrods guides 16 and 16' adjacent the arrnatures '18 readily pivot in their stationary support members 92 and 92', as the opposite ends adjacent the hammers 12 follow the hammers as the support member 26 increments.

With the support member 26 located in an initial print position, different ones of the hammers 12 may be positioned opposite the odd numbered print positions 1-3-5-7, etc. The hammers 12 may be selectively actuated by energizing the operating windings 22 under the control of suitable printer control means until all the characters on the movable type carrying chain, train or belt have been presented to each print position having a hammer opposite it, so as to be optioned for printing. Upon the completion of this portion of the printing cycle, the motor 56 may he stepped by suitable control means (not shown) to move the print hammers to the intervening or even numbered print positions in which a similar optioning of the print hammers may occur, until each and every character has been optioned to each and every print hammer for printing the even positions, whereupon the printing operation will be terminated and the stepping motor 56 again energized to either return the support member directly to its original or initial operating position, or increment it in steps back to the initial position in a plurality of printing operations in a reverse sequence.

Referring to FIGURES 6 and 7, it will be seen that instead of utilizing the pushrod arrangement of a slender pushrod slidably disposed in a guide member as shown in FIGURES 1-5 of the drawings, flat rod-like pushrod members may be utilized, each having a slot or groove 112 at the left end for receiving the central stem portion 68 of a print hammer, and having rounded end portions 114 at the opposite ends for being engaged by the armature 118 of an electromagnetic actuating means. Means such as the stationary side members 115 may be positioned adjacent the end portion 114 to maintain this end of the pushrod 110 in operating relation with a related armature 118. As shown, the rounded end portion 114 permits swiveling of the pushrod 110 when the print hammers are incremented to intervening print positions, without changing the effective operating length of the pushrod. The sidewalls of the slots 112 may be rounded as shown in FIGURE 7, as well as the inner end of the slot so that continuous contact may be maintained with the stem portion 68 of the hammer as it increments from one position to another as shown by the relationship illustrated in dotted lines in FIGURES 6 and 7. For example, a pushrod 110 such as the one shown may be provided for each of positions 15913-17, etc., along the print line, with the print hammers in an initial position. When the print hammers 12 are moved to the next print position, the pushrods 110 will be positioned in positions 2-6-10-14-18, etc.; in the third operating position of the print hammers, the pushrods 110 Will be positioned at print positions 37l l15l7 etc., While in the fourth or final print position the pushrods 110 will be positioned at print positions 4-8-10-16-20, etc. Upon completing printing for the fourth position of the pushrods, the print hammers may be returned to the initial position and the document moved for printing the next line, or the document may be advanced, and the print hammers incremented step by step in the reverse direction, for performing printing operations in each of the print positions as they are returned to the initial position.

From the above description and the accompanying drawings, it will be apparent that the present invention provides a simple and effective multiple spaced print hammer arrangement for a printer. By utilizing the arrangement hereinbefore described, the maximum utilization of the operating mechanism may be obtained while the mass of the moving part of the mechanism which has to be incremented to cover the extreme and intervening print positions, is kept to a minimum. By utilizing spaced apart print hammers and incrementing them in one or more steps to the intervening print positions, a great reduction in the amount of electronics utilized may be effected, together with the economies provided thereby. By utilizing swiveling pushrods for transmitting the action of the electromagnetic actuating means to the print hammers, variations in print quality and errors in print timing are kept to a minimum.

While the invention has been shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. In a printer having a plurality of print positions along a print line and having a movable character bearing type element moving type characters past said print positions,

a print hammer pivotal toward said type element to impact a document and selected type characters, a support movable along the print line pivotally supporting said hammer at one of the print positions,

means for actuating said movable support along the print line to position the hammer at other than said one of said print positions,

stationary actuating means having an actuating mem ber movable in the direction of pivotal movement of the associated hammer,

and means including an elongated pushrod operatively connecting the actuating member and its associated hammer pivotally secured adjacent the actuating member at one end and movable at the other end with the print hammer from one print position toward the next.

2. A printer as defined in claim 1, characterized by the elongated member being secured in operating relation with the movable support at the print hammer end.

3. A printer as defined in claim 2, characterized by 4 member which is pivotally secured to a stationary support adjacent the actuating member and has a portion interfitting with the slot in the movable support at the other end.

5. A printer as defined in claim 3, characterized by the movable support having a plurality of slots positioned opposite spaced apart print positions and each having a pivotally mounted hammer and associated actuating means.

6. A printer as defined in claim 4, characterized by the guide member having a vertical web positioned in the hammer slot of the movable support and a horizontal flange positioned in a horizontal slot along the adjacent side of the movable support.

7. A printer as defined in claim 5, characterized by the movable support being incremented by a rack and pinion drive from a stepping motor.

8. A printer as defined in claim 6, characterized by a plurality of print hammers being pivotally mounted on a common pivot pin located in a horizontal groove on the opposite side of the movable support from the pushrods.

9. A printer as defined in claim 7, characterized by the movable support being slidably mounted on an elongated rod and provided with a depending projection having a guide member extending transversely of the rod and slidably engaging a fixed bearing surface to prevent rotation of the support on the rod under the influence of the pushrods.

10. A printer as defined in claim 1, characterized by the pushrod having a slot providing an interfitting relation with the hammer at one end, and having an accurate surface at the other end engaged by the actuating means.

References Cited UNITED STATES PATENTS 3,012,499 12/1951 Amada 10l93 3,135,195 6/1964 Potter 1 101-93 3,220,343 11/1965 Wasserman 101-111 X 3,241,480 3/1966 Cunningham 101-93 3,253,539 5/1966 Christotf et al 101-93 3,332,343 7/1967 Sims 10193 3,364,852 1/1968 Ragen v 101--93 WILLIAM B. PENN, Primary Examiner.

US. Cl. X.R. l9749 

